Nick, not sure about the dates you give. Here is an interesting account of the PIR patrols crossing the Rhine at/near Cologne in the early April time frame. I was hoping the account might mention the rescue but it stops on April 9, two days before the 11th.
The co-ordinates they are giving are in the Nord de Guerre, wF map square. (see
http://www.echodelta.net/mbs/eng-welcome.php )
The PIR account:
http://ww2tribute.blogspot.com/2014/03/
(NOTE: the patrol reports in the link above were retrieved apparently from an on-line "virtual" Fort Benning library which contained a large pdf file called D97_I2031.pdf.
Unfortunately, the link addresses given for that file no-longer seem to work. That file "may" have information on the rescue. I will try to contact the library and also the author of the blog.)
Here are some maps which shows the front on April 1, 1945 and April 15, 1945. Note that Cologne (east bank side) was in a "pocket" (the Ruhr pocket) with Rhine crossings both to the north and south.
https://upload.wikimedia.org/wikiped...frontAtlas.jpg
https://upload.wikimedia.org/wikiped...frontAtlas.jpg